1. Field of the Invention
This invention relates to personal care compositions, and, more particularly, to sunscreen products in which the active component is trapped within a gel material in a thickened condition.
2. Description of the Prior Art
In recent years, increased awareness of the porentially harmful effects of solar radiation has led to rapid growth in the use of sunscreen products. As sunscreens are usually applied prior to activities such as bathing or sports, the consumer requires a product that will remain effective after exposure to water and/or perspiration.
The use of water-insoluble active sunscreen ingredients is usually insufficient to provide adequate water resistance. A thickener also is required in such formulations. However, an effective method of accomplishing water resistance or waterproofing of a sunscreen formula is to employ a water-insoluble substantive film forming resin. A Carbomer resin can provide thickening action. Typical materials for waterproofing sunscreen formulations are two resins which are copolymers of vinylpyrrolidone and long chain alkanes, C.sub.16 and C.sub.20. They are oil-soluble film forming polymers which have been used for some time by the cosmetics industry. However, it is desired to provide new and improved resins which can provide the thickener property in sunscreen formulation, and contribute to its waterproofing characteristics.